Question 1

Two protons (p1 and p2)are on the x axis, as shown below.The directions of the electric field at points 1, 2, and 3 respectively, are:

Accepted Answer

A) "$\rightarrow$  , $\leftarrow$, $\rightarrow$  " 
B) "$\leftarrow$, $\rightarrow$   , $\leftarrow$" 
C) "$\leftarrow$, $\rightarrow$  , $\rightarrow$  " 
D) "$\leftarrow$, $\leftarrow$, $\leftarrow$" 
E) "$\leftarrow$, $\leftarrow$, $\rightarrow$  " 
A) "$\rightarrow$  , $\leftarrow$, $\rightarrow$  " 
B) "$\leftarrow$, $\rightarrow$   , $\leftarrow$" 
C) "$\leftarrow$, $\rightarrow$  , $\rightarrow$  " 
D) "$\leftarrow$, $\leftarrow$, $\leftarrow$" 
E) "$\leftarrow$, $\leftarrow$, $\rightarrow$  " E

Question 2

An electric dipole is oriented parallel to a uniform electric field, as shown.   It is rotated to one of the five orientations shown below.Rank the final orientations according to the change in the potential energy of the dipole-field system, most negative to most positive.

Accepted Answer

A) 1, 2, 3, 4 
B) 4, 3, 2, 1 
C) 1, 2, 4, 3 
D) 3, then 2 and 4 tie, then 1 
E) 1, then 2 and 4 tie, then 3 
A) 1, 2, 3, 4 
B) 4, 3, 2, 1 
C) 1, 2, 4, 3 
D) 3, then 2 and 4 tie, then 1 
E) 1, then 2 and 4 tie, then 3 A

Question 3

As used in the definition of electric field, a "test charge":

Accepted Answer

A) has zero charge 
B) must be a proton 
C) has charge of magnitude 1.6*10-19 C 
D) must be an electron 
E) none of the above 
A) has zero charge 
B) must be a proton 
C) has charge of magnitude 1.6*10-19 C 
D) must be an electron 
E) none of the above E

Question 4

An electron traveling north enters a region where the electric field is uniform and points north.The electron:

Accepted Answer

A) speeds up 
B) slows down 
C) veers east 
D) veers west 
E) continues with the same speed in the same direction 
A) speeds up 
B) slows down 
C) veers east 
D) veers west 
E) continues with the same speed in the same direction

Question 5

The dipole moment of a dipole in a 300-N/C electric field is initially perpendicular to the field, but it rotates so it is in the same direction as the field.If the moment has a magnitude of 2 *10-9 C.m the work done by the field is:

Accepted Answer

A) -12 *10-7 J 
B) -6 * 10-7 J 
C) 0 J 
D) 6 * 10-7 J 
E) 12 * 10-7 J 
A) -12 *10-7 J 
B) -6 * 10-7 J 
C) 0 J 
D) 6 * 10-7 J 
E) 12 * 10-7 J

Question 6

The diagram shows the electric field lines in a region of space containing two small charged spheres (Y and Z).Then:

Accepted Answer

A) Y is negative and Z is positive 
B) the magnitude of the electric filed is the same everywhere 
C) the electric field is strongest midway between Y and Z 
D) Y is positive and Z is negative 
E) Y and Z must have the same sign 
A) Y is negative and Z is positive 
B) the magnitude of the electric filed is the same everywhere 
C) the electric field is strongest midway between Y and Z 
D) Y is positive and Z is negative 
E) Y and Z must have the same sign

Question 7

A charged oil drop with a mass of 2 *10-4 kg is held suspended by a downward electric field of 300 N/C.The charge on the drop is:

Accepted Answer

A) +1.5 *106 C 
B) -1.5 * 106 C 
C) +6.5 * 10-6 C 
D) -6.5 *10-6 C 
E) 0 C 
A) +1.5 *106 C 
B) -1.5 * 106 C 
C) +6.5 * 10-6 C 
D) -6.5 *10-6 C 
E) 0 C

Question 8

A disk with a uniform positive surface charge density lies in the x-y plane, centered on the origin.Along the positive z axis, the direction of the electric field is:

Accepted Answer

A) in the +z direction 
B) in the -z direction 
C) in the +x direction 
D) in the +y direction 
E) there is no field along the positive z axis 
A) in the +z direction 
B) in the -z direction 
C) in the +x direction 
D) in the +y direction 
E) there is no field along the positive z axis

Question 9

Experimenter A uses a test charge q0 and experimenter B uses a test charge 2q0 to measure an electric field produced by stationary charges.A finds a field that is:

Accepted Answer

A) the same as the field found by B 
B) greater than the field found by B 
C) less than the field found by B 
D) either greater or less than the field found by B, depending on the masses of the test charges 
E) either greater or less than the field found by B, depending on the accelerations of the test charges 
A) the same as the field found by B 
B) greater than the field found by B 
C) less than the field found by B 
D) either greater or less than the field found by B, depending on the masses of the test charges 
E) either greater or less than the field found by B, depending on the accelerations of the test charges

Question 10

A charged particle is placed in an electric field that varies with location.No force is exerted on this charge:

Accepted Answer

A) at locations where the electric field is zero 
B) at locations where the electric field strength is 1/(1.6 * 10-19)N/C 
C) if the particle is moving along a field line 
D) if the particle is moving perpendicular to a field line 
E) if the field is caused by an equal amount of positive and negative charge 
A) at locations where the electric field is zero 
B) at locations where the electric field strength is 1/(1.6 * 10-19)N/C 
C) if the particle is moving along a field line 
D) if the particle is moving perpendicular to a field line 
E) if the field is caused by an equal amount of positive and negative charge

Question 11

A disk with a uniform positive surface charge density lies in the x-y plane, centered on the origin.The disk contains 2.5 x 10-6 C/m2 of charge, and is 7.5 cm in radius.What is the electric field at z = 15 cm?

Accepted Answer

A) 30 N/C 
B) 300 N/C 
C) 3000 N/C 
D) 3.0 x 104 N/C 
E) 3.0 x 107 N/C 
A) 30 N/C 
B) 300 N/C 
C) 3000 N/C 
D) 3.0 x 104 N/C 
E) 3.0 x 107 N/C

Question 12

The torque exerted by an electric field on a dipole is:

Accepted Answer

A) parallel to the field and perpendicular to the dipole moment 
B) parallel to both the field and dipole moment 
C) perpendicular to both the field and dipole moment 
D) parallel to the dipole moment and perpendicular to the field 
E) not related to the directions of the field and dipole moment 
A) parallel to the field and perpendicular to the dipole moment 
B) parallel to both the field and dipole moment 
C) perpendicular to both the field and dipole moment 
D) parallel to the dipole moment and perpendicular to the field 
E) not related to the directions of the field and dipole moment

Question 13

Two point particles, with the same charge, are located at two vertices of an equilateral triangle.A third charged particle is placed so the electric field at the third vertex is zero.The third particle must:

Accepted Answer

A) be on the perpendicular bisector of the line joining the first two charges 
B) be on the line joining the first two charges 
C) be identical to the first two charges 
D) have the same magnitude as the first two charges but may have a different sign 
E) be at the center of the triangle 
A) be on the perpendicular bisector of the line joining the first two charges 
B) be on the line joining the first two charges 
C) be identical to the first two charges 
D) have the same magnitude as the first two charges but may have a different sign 
E) be at the center of the triangle

Question 14

An electric field exerts a torque on a dipole only if:

Accepted Answer

A) the field is parallel to the dipole moment 
B) the field is not parallel to the dipole moment 
C) the field is perpendicular to the dipole moment 
D) the field is not perpendicular to the dipole moment 
E) the field is uniform 
A) the field is parallel to the dipole moment 
B) the field is not parallel to the dipole moment 
C) the field is perpendicular to the dipole moment 
D) the field is not perpendicular to the dipole moment 
E) the field is uniform

Question 15

A total charge of 6.3 *10-8 C is distributed uniformly throughout a 2.7-cm radius sphere.The volume charge density is:

Accepted Answer

A) 3.7 *10-7 C/m3 
B) 6.9*10-6 C/m3 
C) 6.9 *10-6 C/m2 
D) 2.5 * 10-4 C/m3 
E) 7.6 * 10-4 C/m3 
A) 3.7 *10-7 C/m3 
B) 6.9*10-6 C/m3 
C) 6.9 *10-6 C/m2 
D) 2.5 * 10-4 C/m3 
E) 7.6 * 10-4 C/m3

Question 16

The diagrams below depict four different charge distributions.The charged particles are all the same distance from the origin.The electric field at the origin:

Accepted Answer

A) is least for situation 1 
B) is greatest for situation 3 
C) is zero for situation 4 
D) is downward for situation 1 
E) is downward for situation 3 
A) is least for situation 1 
B) is greatest for situation 3 
C) is zero for situation 4 
D) is downward for situation 1 
E) is downward for situation 3

Question 17

The diagram shows two identical particles, each with positive charge Q.The electric field at point P on the perpendicular bisector of the line joining them is:

Accepted Answer

A) "$\uparrow$" 
B) "$\downarrow$" 
C) "$\rightarrow$" 
D) "$\leftarrow$" 
E) "zero" 
A) "$\uparrow$" 
B) "$\downarrow$" 
C) "$\rightarrow$" 
D) "$\leftarrow$" 
E) "zero"

Question 18

The purpose of Milliken's oil drop experiment was to determine:

Accepted Answer

A) the mass of an electron 
B) the charge of an electron 
C) the ratio of charge to mass for an electron 
D) the sign of the charge on an electron 
E) viscosity 
A) the mass of an electron 
B) the charge of an electron 
C) the ratio of charge to mass for an electron 
D) the sign of the charge on an electron 
E) viscosity

Question 19

An isolated charged point particle produces an electric field with magnitude E at a point 2 m away.At a point 1 m from the particle the magnitude of the field is:

Accepted Answer

A) E 
B) 2E 
C) 4E 
D) E/2 
E) E/4 
A) E 
B) 2E 
C) 4E 
D) E/2 
E) E/4

Question 20

Two point particles, with charges of q1 and q2, are placed a distance r apart.The electric field is zero at a point P between the particles on the line segment connecting them.We conclude that:

Accepted Answer

A) q1 and q2 must have the same magnitude and sign 
B) P must be midway between the particles 
C) q1 and q2 must have the same sign but may have different magnitudes 
D) q1 and q2 must have equal magnitudes and opposite signs 
E) q1 and q2 must have opposite signs and may have different magnitudes 
A) q1 and q2 must have the same magnitude and sign 
B) P must be midway between the particles 
C) q1 and q2 must have the same sign but may have different magnitudes 
D) q1 and q2 must have equal magnitudes and opposite signs 
E) q1 and q2 must have opposite signs and may have different magnitudes

Exam 22: Electric Fields

Two protons (p1 and p2)are on the x axis, as shown below.The directions of the electric field at points 1, 2, and 3 respectively, are:

An electric dipole is oriented parallel to a uniform electric field, as shown. It is rotated to one of the five orientations shown below.Rank the final orientations according to the change in the potential energy of the dipole-field system, most negative to most positive.

As used in the definition of electric field, a "test charge":

An electron traveling north enters a region where the electric field is uniform and points north.The electron:

The dipole moment of a dipole in a 300-N/C electric field is initially perpendicular to the field, but it rotates so it is in the same direction as the field.If the moment has a magnitude of 2 *10-9 C.m the work done by the field is:

The diagram shows the electric field lines in a region of space containing two small charged spheres (Y and Z).Then:

A charged oil drop with a mass of 2 *10-4 kg is held suspended by a downward electric field of 300 N/C.The charge on the drop is:

A disk with a uniform positive surface charge density lies in the x-y plane, centered on the origin.Along the positive z axis, the direction of the electric field is:

Experimenter A uses a test charge q0 and experimenter B uses a test charge 2q0 to measure an electric field produced by stationary charges.A finds a field that is:

A charged particle is placed in an electric field that varies with location.No force is exerted on this charge:

A disk with a uniform positive surface charge density lies in the x-y plane, centered on the origin.The disk contains 2.5 x 10-6 C/m2 of charge, and is 7.5 cm in radius.What is the electric field at z = 15 cm?

The torque exerted by an electric field on a dipole is:

Two point particles, with the same charge, are located at two vertices of an equilateral triangle.A third charged particle is placed so the electric field at the third vertex is zero.The third particle must:

An electric field exerts a torque on a dipole only if:

A total charge of 6.3 *10-8 C is distributed uniformly throughout a 2.7-cm radius sphere.The volume charge density is:

The diagrams below depict four different charge distributions.The charged particles are all the same distance from the origin.The electric field at the origin:

The diagram shows two identical particles, each with positive charge Q.The electric field at point P on the perpendicular bisector of the line joining them is:

The purpose of Milliken's oil drop experiment was to determine:

An isolated charged point particle produces an electric field with magnitude E at a point 2 m away.At a point 1 m from the particle the magnitude of the field is:

Two point particles, with charges of q1 and q2, are placed a distance r apart.The electric field is zero at a point P between the particles on the line segment connecting them.We conclude that:

Measurement

Motion Along a Straight Line

Vector

Motion in Two and Three Dimensions

Force and Motion I

Force and Motion II

Kinetic Energy and Work

Potential Energy and Conservation of Energy

Center of Mass and Linear Momentum

Rotation

Rolling, Torque, and Angular Momentum

Equilibrium and Elasticity

Gravitation

Fluids

Oscillations

Waves I

Waves II

Temperature, Heat, and the First Law of Thermodynamics

The Kinetic Theory of Gases

Entropy and the Second Law of Thermodynamics

Electric Charge

Gauss Law

Electric Potential

Capacitance

Current and Resistance

Circuits

Magnetic Fields

Magnetic Fields Due to Currents

Induction and Inductance

Electromagnetic Oscillations and Alternating Current

Maxwells Equations; Magnetism of Matter

Electromagnetic Waves

Images

Interference

Diffraction

Relativity

Photons and Matter Waves

More About Matter Waves

All About Atoms

Conduction of Electricity in Solids

Nuclear Physics

Energy From the Nucleus

Quarks, Leptons, and the Big Bang

Filters

Two protons (p₁ and p₂)are on the x axis, as shown below.The directions of the electric field at points 1, 2, and 3 respectively, are:

The dipole moment of a dipole in a 300-N/C electric field is initially perpendicular to the field, but it rotates so it is in the same direction as the field.If the moment has a magnitude of 2 *10^-9 C.m the work done by the field is:

A charged oil drop with a mass of 2 *10^-4 kg is held suspended by a downward electric field of 300 N/C.The charge on the drop is:

Experimenter A uses a test charge q₀ and experimenter B uses a test charge 2q₀ to measure an electric field produced by stationary charges.A finds a field that is:

A disk with a uniform positive surface charge density lies in the x-y plane, centered on the origin.The disk contains 2.5 x 10^-6 C/m² of charge, and is 7.5 cm in radius.What is the electric field at z = 15 cm?

A total charge of 6.3 *10^-8 C is distributed uniformly throughout a 2.7-cm radius sphere.The volume charge density is:

Two point particles, with charges of q₁ and q₂, are placed a distance r apart.The electric field is zero at a point P between the particles on the line segment connecting them.We conclude that: